compare checkbox value on submit and display message using php - php

Question

I want to display the message when user clicks on Others checkbox. There are other checkboxes too so I want to compare checkbox value and if Others checkbox is selected then I want to display the message. This is my code:
<input type="checkbox" name="subject[]" value="Subject-1+Subject-2">Subject-1+Subject-2
<input type="checkbox" name="subject[]" value="Subject-1+Subject-2+Subject-3">Subject-1+Subject-2+Subject-3
<input type="checkbox" name="subject[]" value="Others">Others
<input type="submit" value="Submit" name="submit" class="wpcf7-submit"><br><br>
php part:
if(isset($_POST['submit']))
{
if(!empty($_POST['subject']) && $_POST['subject']=="Others") {
echo " <SCRIPT LANGUAGE='Javascript'>
window.alert('You wish to select other combo apart from given in above list. Kindly contact incharge of this institute.');
</SCRIPT>";
}
}
This code is not working. What changes should I make??

Answer 1

As subject[] is an array in
<input type="checkbox" name="subject[]" value="Others">
is an array type. So you should validate subject field as array as follows:
if (isset($_POST['submit'])) {
if (!empty($_POST['subject']) && in_array("Others", $_POST['subject'])) {
echo " <SCRIPT LANGUAGE='Javascript'>
window.alert('You wish to select other combo apart from given in above list. Kindly contact incharge of this institute.');
</SCRIPT>";
}
}

Answer 2

You can try something like given below. you are free to use in_array() but if you want to use the second condition with it use foreach like this.
if (in_array("Others", $_POST['subject'])) {
echo 'selected ';
}
else{
//do something
}
OR
if(isset($_POST['submit']))
{
$results=$_POST['subject'];
foreach ($results as $result) {
if ($result==='Others') {
echo 'selected ';
}
else{
//do something
}
}
}

Answer 3

<?php
if(isset($_POST['submit']) && $_POST['submit']=="Submit"){
if(isset($_POST['subject'])){
$subject = $_POST['subject'];
if(in_array('Others', $subject)){
echo "<script>alert('You wish to select other combo apart from given in above list. Kindly contact incharge of this institute.');</script>";
}
}else{
echo "<script>alert('You wish to select other combo apart from given in above list. Kindly contact incharge of this institute.');</script>";
}
}
?>
<form method="POST" action="">
<input type="checkbox" name="subject[]" value="Subject-1+Subject-2">Subject-1+Subject-2
<input type="checkbox" name="subject[]" value="Subject-1+Subject-2+Subject-3">Subject-1+Subject-2+Subject-3
<input type="checkbox" name="subject[]" value="Others">Others
<input type="submit" value="Submit" name="submit" class="wpcf7-submit"><br><br>
</form>